Are insullation baffles needed?

[S4PLAY]

from what little research I have done, it seems that baffles are needed if I am doing blown in insulation but not really if I am doing batts. Am I wrong?

I do not have an attic or even crawl space. The garage is cathedral cielings and will be completly closed in at the top flat of the cieling.

 

[ClickClickBoom]

If you're doing cathedral ceilings, then you won't have a vented ceilings, so baffles definitely aren't needed.

baffles are basically used to make blow in insulation easier. You don't need them, but it makes it easier to maintain the air channels from the soffits to the roof. Without them, you need to be careful not to full the soffits with instulation when blowing.

 

[Spudland_Dave]

"needed" probably not...but for 1.50 each, IMO why not...one less thing to worry about. I used them in my garage even tho I used Batt insulation. IF I ever want to blow in a couple inches on top, its no issue at all. I can only imagine how much of a PITA it would be to do it after the fact.

 

[ForceFed70]

"needed" probably not...but for 1.50 each, IMO why not...one less thing to worry about. I used them in my garage even tho I used Batt insulation. IF I ever want to blow in a couple inches on top, its no issue at all. I can only imagine how much of a PITA it would be to do it after the fact.

Exactly what I was going to say.

Not needed for batt but cheap to put in and could save headaches later.

 

[Highbeam]

The purpose of these baffles is to prevent blocking the air passage between the soffit and the ridge. This air passage is necessary to carry away heat and moisture in most roof systems. If you can install the insulation without blocking the ventilation from the soffits then the baffles are not needed.

Some cathedral ceiling jobs allow space for air to pass between the insulation and the roof deck and this is to be maintained.

In my pole barn the baffles would not work so I am planning to install thick batts near the edge of the ceiling while maintaining the ventilation and then blowing in the center of the ceiling.

So no, you don't need them but you need to provide their function.

 

[ishiboo]

There are vented roofs and non-vented roofs ("hot decks" or something the roofers call them). The supposed idea was even in a closed ceiling with no moisture/etc problems that an attic would have, circulating air under the roof deck would keep the roof cooler and prevent premature roofing material failure. (asphalt shingles). This has been proven to be pretty much untrue.

So, if this is a cathedral ceiling and you will not be providing an air gap everywhere, you should not install baffles - they serve no purpose - and you should not have venting.

It's not a "for $X why not", they serve ZERO purpose and will actually harm the insulation value. Fill the entire cavity with the batts.

 

[Falcon67]

Depends. The bottom line is to cover the top of the wall plates with insulation. Blown is really poor about that and if you try too hard, you'll plug up the soffit. There is also a thing called "wind washing". In the areas where you have soffit vents, strong air currents can move air under and around the ends of the batts, effectively negating the insulation. That's pretty much a site and construction dependent item.

 

[S4PLAY]

So this is what im working with if it helps...

To baffle or Not to baffle?

 

[BigGMC]

So now, it's not detremental to have no under deck ventilation with a cath. design?
I know that has been my latest quandry - venting my attic truss portion will eatup about 2" of space, leaving me with less than desireable insualtion room. Thought about building up the interior side of trusses to recoup that cavity depth loss.